Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as ... more Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS N+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS N+ radical with a second order rate constant of 2.33610 6 and 1.72610 6 , respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48610 6 and 4.46610 6 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C 27 H 42 O 3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants.
Background: Micro (mi)RNAs are important regulators of plant development. Across plant lineages, ... more Background: Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1 (DCL1) proteins process long ds-like structures to produce micro (mi) RNA duplexes in a stepwise manner. These miRNAs are incorporated into Argonaute (AGO) proteins and influence expression of RNAs that have sequence complementarity with miRNAs. Expression levels of AGOs are greatly regulated by plants in order to minimize unwarranted perturbations using miRNAs to target mRNAs coding for AGOs. AGOs may also have high promoter specificity-sometimes expression of AGO can be limited to just a few cells in a plant. Viral pathogens utilize various means to counter antiviral roles of AGOs including hijacking the host encoded miRNAs to target AGOs. Two host encoded miRNAs namely miR168 and miR403 that target AGOs have been described in the model plant Arabidopsis and such a mechanism is thought to be well conserved across plants because AGO sequences are well conserved. Results: We show that the interaction between AGO mRNAs and miRNAs is species-specific due to the diversity in sequences of two miRNAs that target AGOs, sequence diversity among corresponding target regions in AGO mRNAs and variable expression levels of these miRNAs among vascular plants. We used miRNA sequences from 68 plant species representing 31 plant families for this analysis. Sequences of miR168 and miR403 are not conserved among plant lineages, but surprisingly they differ drastically in their sequence diversity and expression levels even among closely related plants. Variation in miR168 expression among plants correlates well with secondary structures/length of loop sequences of their precursors. Conclusions: Our data indicates a complex AGO targeting interaction among plant lineages due to miRNA sequence diversity and sequences of miRNA targeting regions among AGO mRNAs, thus leading to the assumption that the perturbations by viruses that use host miRNAs to target antiviral AGOs can only be species-specific. We also show that rapid evolution and likely loss of expression of miR168 isoforms in tobacco is related to the insertion of MITE-like transposons between miRNA and miRNA* sequences, a possible mechanism showing how miRNAs are lost in few plant lineages even though other close relatives have abundantly expressing miRNAs.
Background: Biological route for synthesis of copper nanoparticles (CuNPs) with therapeutic poten... more Background: Biological route for synthesis of copper nanoparticles (CuNPs) with therapeutic potential is a major challenge. In this study, CuNPs were synthesized by D. bulbifera tuber extract (DBTE) which were further evaluated for antidiabetic and free radical scavenging activity. Methods: CuNPs synthesized by DBTE were characterized by UV-visible spectroscopy, transmission electron microscopy, energy dispersive spectroscopy and dynamic light scattering. CuNPs were checked for α-amylase and α-glucosidase inhibition along with interaction studies employing fluroscence spectroscopy, circular dichroism spectroscopy and computational docking. DPPH, nitric oxide and superoxide radical scavenging activities of CuNPs were also checked. Results: Spherical monodispersed CuNPs were synthesized within 5 h that was indicated by a colour change from pale blue to brown. Majority of the nanoparticles synthesized were found to be between 12 to 16 nm as showed in DLS which grew till a final size of 86 to 126 nm as indicated in TEM. Bioreduced CuNPs showed 38.70 ± 1.45% and 34.72 ± 1.22% inhibition against porcine and murine pancreatic amylase, respectively with an uncompetitive mode that was further confirmed by docking studies. Fluorescence spectroscopy confirmed the interaction of CuNPs to the enzyme via Trp residues while CD spectra indicated the structural and conformational changes on binding of CuNPs to the enzyme. CuNPs exhibited 99.09 ± 0.15% inhibition against α-glucosidase while 90.67 ± 0.33% inhibition against murine intestinal glucosidase, respectively. CuNPs showed 40.81 ± 1.44%, 79.06 ± 1.02% and 48.39 ± 1.46% scavenging activity against DPPH, nitric oxide and superoxide radicals respectively. Conclusion: D.bulbifera tuber extract mediated bioreduction is most rapid route to synthesize novel CuNPs with promising antidiabetic and antioxidant properties. This is the first detailed report which provides intense scientific rationale for the use of CuNPs as nanomedicine for efficient control of T2DM and oxidative stress.
Dioscorea bulbiferais a potent medicinal plant used in both Indian and Chinese traditional medici... more Dioscorea bulbiferais a potent medicinal plant used in both Indian and Chinese traditional medicine owing to its rich phytochemical diversity. Herein, we report the rapid synthesis of novelAucoreAgshellnanoparticles byD. bulbiferatuber extract (DBTE).AucoreAgshellNPs synthesis was completed within 5 h showing a prominent peak at 540 nm. HRTEM analysis revealed 9 nm inner core of elemental gold covered by a silver shell giving a total particle diameter upto 15 nm.AucoreAgshellNPs were comprised of57.34±1.01% gold and42.66±0.97% silver of the total mass.AucoreAgshellNPs showed highest biofilm inhibition upto83.68±0.09% againstA. baumannii. Biofilms ofP. aeruginosa,E. coli, andS. aureuswere inhibited up to18.93±1.94%,22.33±0.56%, and30.70±1.33%, respectively. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed unregulated cellular efflux through pore formation leading to cell death. Potent antileishmanial activity ofAucoreAgshellNPs (MIC=32 µg/mL) was confirm...
Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1... more Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1 (DCL1) proteins process long ds-like structures to produce micro (mi) RNA duplexes in a stepwise manner. These miRNAs are incorporated into Argonaute (AGO) proteins and influence expression of RNAs that have sequence complementarity with miRNAs. Expression levels of AGOs are greatly regulated by plants in order to minimize unwarranted perturbations using miRNAs to target mRNAs coding for AGOs. AGOs may also have high promoter specificity-sometimes expression of AGO can be limited to just a few cells in a plant. Viral pathogens utilize various means to counter antiviral roles of AGOs including hijacking the host encoded miRNAs to target AGOs. Two host encoded miRNAs namely miR168 and miR403 that target AGOs have been described in the model plant Arabidopsis and such a mechanism is thought to be well conserved across plants because AGO sequences are well conserved. We show that the intera...
Dioscorea bulbifera is a potentmedicinal plant used in both Indian andChinese traditional medicin... more Dioscorea bulbifera is a potentmedicinal plant used in both Indian andChinese traditional medicine owing to its rich phytochemical diversity.Herein,we report the rapid synthesis of novelAucoreAgshell nanoparticles by D. bulbifera tuber extract (DBTE).AucoreAgshell NPs synthesis was completed within 5 h showing a prominent peak at 540 nm. HRTEM analysis revealed 9nm inner core of elemental gold covered by a silver shell giving a total particle diameter upto 15 nm. AucoreAgshellNPs were comprised of 57.34±1.01% gold and 42.66 ± 0.97% silver of the total mass. AucoreAgshellNPs showed highest biofilm inhibition upto 83.68 ± 0.09% against A. baumannii. Biofilms of P. aeruginosa, E. coli, and S. aureus were inhibited up to 18.93 ± 1.94%, 22.33 ± 0.56%, and 30.70 ± 1.33%, respectively. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed unregulated cellular efflux through pore formation leading to cell death. Potent antileishmanial activity of AucoreAgshellNPs (M...
Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as ... more Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS N+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS N+ radical with a second order rate constant of 2.33610 6 and 1.72610 6 , respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48610 6 and 4.46610 6 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C 27 H 42 O 3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants.
Background: Micro (mi)RNAs are important regulators of plant development. Across plant lineages, ... more Background: Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1 (DCL1) proteins process long ds-like structures to produce micro (mi) RNA duplexes in a stepwise manner. These miRNAs are incorporated into Argonaute (AGO) proteins and influence expression of RNAs that have sequence complementarity with miRNAs. Expression levels of AGOs are greatly regulated by plants in order to minimize unwarranted perturbations using miRNAs to target mRNAs coding for AGOs. AGOs may also have high promoter specificity-sometimes expression of AGO can be limited to just a few cells in a plant. Viral pathogens utilize various means to counter antiviral roles of AGOs including hijacking the host encoded miRNAs to target AGOs. Two host encoded miRNAs namely miR168 and miR403 that target AGOs have been described in the model plant Arabidopsis and such a mechanism is thought to be well conserved across plants because AGO sequences are well conserved. Results: We show that the interaction between AGO mRNAs and miRNAs is species-specific due to the diversity in sequences of two miRNAs that target AGOs, sequence diversity among corresponding target regions in AGO mRNAs and variable expression levels of these miRNAs among vascular plants. We used miRNA sequences from 68 plant species representing 31 plant families for this analysis. Sequences of miR168 and miR403 are not conserved among plant lineages, but surprisingly they differ drastically in their sequence diversity and expression levels even among closely related plants. Variation in miR168 expression among plants correlates well with secondary structures/length of loop sequences of their precursors. Conclusions: Our data indicates a complex AGO targeting interaction among plant lineages due to miRNA sequence diversity and sequences of miRNA targeting regions among AGO mRNAs, thus leading to the assumption that the perturbations by viruses that use host miRNAs to target antiviral AGOs can only be species-specific. We also show that rapid evolution and likely loss of expression of miR168 isoforms in tobacco is related to the insertion of MITE-like transposons between miRNA and miRNA* sequences, a possible mechanism showing how miRNAs are lost in few plant lineages even though other close relatives have abundantly expressing miRNAs.
Background: Biological route for synthesis of copper nanoparticles (CuNPs) with therapeutic poten... more Background: Biological route for synthesis of copper nanoparticles (CuNPs) with therapeutic potential is a major challenge. In this study, CuNPs were synthesized by D. bulbifera tuber extract (DBTE) which were further evaluated for antidiabetic and free radical scavenging activity. Methods: CuNPs synthesized by DBTE were characterized by UV-visible spectroscopy, transmission electron microscopy, energy dispersive spectroscopy and dynamic light scattering. CuNPs were checked for α-amylase and α-glucosidase inhibition along with interaction studies employing fluroscence spectroscopy, circular dichroism spectroscopy and computational docking. DPPH, nitric oxide and superoxide radical scavenging activities of CuNPs were also checked. Results: Spherical monodispersed CuNPs were synthesized within 5 h that was indicated by a colour change from pale blue to brown. Majority of the nanoparticles synthesized were found to be between 12 to 16 nm as showed in DLS which grew till a final size of 86 to 126 nm as indicated in TEM. Bioreduced CuNPs showed 38.70 ± 1.45% and 34.72 ± 1.22% inhibition against porcine and murine pancreatic amylase, respectively with an uncompetitive mode that was further confirmed by docking studies. Fluorescence spectroscopy confirmed the interaction of CuNPs to the enzyme via Trp residues while CD spectra indicated the structural and conformational changes on binding of CuNPs to the enzyme. CuNPs exhibited 99.09 ± 0.15% inhibition against α-glucosidase while 90.67 ± 0.33% inhibition against murine intestinal glucosidase, respectively. CuNPs showed 40.81 ± 1.44%, 79.06 ± 1.02% and 48.39 ± 1.46% scavenging activity against DPPH, nitric oxide and superoxide radicals respectively. Conclusion: D.bulbifera tuber extract mediated bioreduction is most rapid route to synthesize novel CuNPs with promising antidiabetic and antioxidant properties. This is the first detailed report which provides intense scientific rationale for the use of CuNPs as nanomedicine for efficient control of T2DM and oxidative stress.
Dioscorea bulbiferais a potent medicinal plant used in both Indian and Chinese traditional medici... more Dioscorea bulbiferais a potent medicinal plant used in both Indian and Chinese traditional medicine owing to its rich phytochemical diversity. Herein, we report the rapid synthesis of novelAucoreAgshellnanoparticles byD. bulbiferatuber extract (DBTE).AucoreAgshellNPs synthesis was completed within 5 h showing a prominent peak at 540 nm. HRTEM analysis revealed 9 nm inner core of elemental gold covered by a silver shell giving a total particle diameter upto 15 nm.AucoreAgshellNPs were comprised of57.34±1.01% gold and42.66±0.97% silver of the total mass.AucoreAgshellNPs showed highest biofilm inhibition upto83.68±0.09% againstA. baumannii. Biofilms ofP. aeruginosa,E. coli, andS. aureuswere inhibited up to18.93±1.94%,22.33±0.56%, and30.70±1.33%, respectively. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed unregulated cellular efflux through pore formation leading to cell death. Potent antileishmanial activity ofAucoreAgshellNPs (MIC=32 µg/mL) was confirm...
Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1... more Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1 (DCL1) proteins process long ds-like structures to produce micro (mi) RNA duplexes in a stepwise manner. These miRNAs are incorporated into Argonaute (AGO) proteins and influence expression of RNAs that have sequence complementarity with miRNAs. Expression levels of AGOs are greatly regulated by plants in order to minimize unwarranted perturbations using miRNAs to target mRNAs coding for AGOs. AGOs may also have high promoter specificity-sometimes expression of AGO can be limited to just a few cells in a plant. Viral pathogens utilize various means to counter antiviral roles of AGOs including hijacking the host encoded miRNAs to target AGOs. Two host encoded miRNAs namely miR168 and miR403 that target AGOs have been described in the model plant Arabidopsis and such a mechanism is thought to be well conserved across plants because AGO sequences are well conserved. We show that the intera...
Dioscorea bulbifera is a potentmedicinal plant used in both Indian andChinese traditional medicin... more Dioscorea bulbifera is a potentmedicinal plant used in both Indian andChinese traditional medicine owing to its rich phytochemical diversity.Herein,we report the rapid synthesis of novelAucoreAgshell nanoparticles by D. bulbifera tuber extract (DBTE).AucoreAgshell NPs synthesis was completed within 5 h showing a prominent peak at 540 nm. HRTEM analysis revealed 9nm inner core of elemental gold covered by a silver shell giving a total particle diameter upto 15 nm. AucoreAgshellNPs were comprised of 57.34±1.01% gold and 42.66 ± 0.97% silver of the total mass. AucoreAgshellNPs showed highest biofilm inhibition upto 83.68 ± 0.09% against A. baumannii. Biofilms of P. aeruginosa, E. coli, and S. aureus were inhibited up to 18.93 ± 1.94%, 22.33 ± 0.56%, and 30.70 ± 1.33%, respectively. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed unregulated cellular efflux through pore formation leading to cell death. Potent antileishmanial activity of AucoreAgshellNPs (M...
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